Transmitter mouthpiece



April 3, 1928.

H. F. DODGE TRANSMITTER MOUTHPIECE Filed Dec. 30. 1922 hvenfon- Harof;f. Dodge. by

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Patented Apr. 3, 1928.

UNITED STATES PATENT OFFICE.

HAROLD F. DODGE, OF NEW YORK, N, Y ASSIGNOR TO WESTERN ELECTRIC COMPANY,INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TRANSMITTER MoU'rHPIEoE.

Application filed December 30, 1922.

This invention relates to transmitter mouthpieces and the object is theimprovement of the quality and the articulation from a transmissionstandpoint.

In accordance with the general features of this invention there isprovided a mouthpiece which will offer a minimum external reflectingsurface to impinging sound waves and will prevent the emphasis of thehiss ng and the explosive sounds in speech, which involve windage,without loss in articulation.

In its preferred form the mouthpiece is in the form of a shell having aplane face provided with a plurality of elongated slots or openingstapered inwardly, said slots being so positioned that planes bisectingthe slots along their greatest dimensions are parallel to the averagedirection of talking.

Referring to the drawing;

Fig. 1 shows a side view of a hand set, part in section, having atransmitter mouthpiece embodying the invention;

Fig. 2 is a plan view of the mouthpiece;

Fig. 3 is an enlarged section showing the shape of the openings in theirpreferred form;

5 and 6 show modifications in the shape of the openings.

On the handle 3, there is mounted at one end a receiver 4 of anysuitable type and on the opposite end a transmitter 6 which is providedwith a mouthpiece 7 preferably of phenol plastic compound. having anannular portion 9 and a perforated face 14 preferably integraltherewith, oblique to the axis of said annular portion. The annularportion 9 may be provided with a plurality of slots 10 through whichscrews 11 secure the mouthpiece 7 to the transmitter case 17. The slots10 are preferably counter sunk at one end to receive the heads of thescrews 11. The perforations in the face 14 are formed by parallel bars12, one side, 13, of each bar being preferably substantiallyperpendicular to the face 14 and the opposite side 15 being obliquethereto. The sides of adjacent bars form long, narrow openings havingconverging walls with the Planes bisecting the openings along theirgreatest dimensions parallel to each other and to the average directionof sound propagation, which ar- SLIial No. 610,000.

rangement minimizes the windage eficct-s of hissing and explosivesounds. Joining the bars 12 is a rib 16 for the purpose of reinforcementwhen the mouthpiece is made of phenol plastic compound or similarmaterials. lVhen the mouthpiece is made of metal, such as brass oraluminum, this reinforcing member may be omitted.

\Vhat is claimed is:

1. A transmitter mouthpiece having a grid formed of a plurality ofparallel bars forming openings of greater dimensions at one side than atthe other.

2. A transmitter mouthpiece having a plane face of uniform thickness,said face comprising a plurality of laterally elongated openings, saidopenings being of larger dimensions at the top than they are at thebottom.

3. A transmitter mouthpiece having a grid formed by parallel bars havingoppositely diverging sides, said bars so disposed that their adjacentsides form long, narrow apertures having converging walls.

4. A transmitter mouthpiece having parallel bars, the adjacent barsforming long, narrow openings with converging walls, the planesbisecting said openings along their greatest dimensions being parallelto each other and extending in the direction of sound propagation.

5. A transmitter mouthpiece comprising a grid having long, narrow bars,one side of each bar being substantially perpendicular to the face ofsaid grid and the opposite side oblique thereto, adjacent bars therebyformng long narrow openings having convergmg walls.

6. In a transmitter, a diaphragm and a mouthpiece having a grid faceoblique to said diaphragm, said grid being formed by a plurality ofparallel bars having diverging sides.

7. A transmitter, a diaphragm, a mouthpiece having an annular portionand a grid portion oblique thereto, said grid portion being formed by aplurality of parallel bars having diverging sides, the sides of adjacentbars forming openings, the planes bisecting the openings along theirgreatest dimeisions being oblique to the face of said gri 8. In atelephone hand set, a transmitter and a mouthpiece for said transmitterhaving a plurality of bars transverse to the medial plane of said handset, said bars having diverging sides forming slots having parallel axesin the direction of sound propagation.

9. In a telephone hand set, a transmitter comprising a mouthpiece havinga plurality of bars transverse to the medial plane of 10 said hand set,and forming openings therein having opposite diverging sides oblique t0the face of said mouthpiece.

In Witness whereof, I hereunto subscribe my name this 28th day oi"December A. D., 15

HAROLD F. DODGE.

